Had a nasty snow storm come through tonight, and while I only took one video had some observations about the selec terrain system on my Wife's ADII Cherokee.
We were going through some unplowed roads with up to 12" of snow and as long as the speed was kept up no problems getting through them. Obviously the stock tires are terrible in the deep snow (as my other video showed). But we played around mode with the selec terrain modes.
We found that with ESC in "full off" mode and putting the selec terrain in "snow" mode going through the deep snow worked very well, without using 4x4 low. When we did try to use the sand/mud mode it seemed to not work as well, it allowed lots of wheel spin but it didn't transfer power across each axle with the BLD (Brake lock differential as aggressively as I would have thought). When using the snow mode the BLD seems to be more aggressive and keep both wheels on the same axle spinning more.
In this video we were on a somewhat steep icey/snow hill. Cherokee is in 4x4 low and Sand/Mud to start, then after the pause my wife puts it into the snow mode, and it was like magic, it went up the hill like nothing.
Snow mode works as intended it seems and very well. One thing about the snow mode is it starts in 2nd gear, however you can still make it start in 1st gear if you slide the gear shift over and select "1".
So with all the messing around in snow, we found snow mode with esc full off and without 4x4 lock to be sufficient 90% of the time. Only using 4x4 low when we got partially stuck (had my jeep out too, just in case).
In no way are these tests scientific but as time goes on I want to do more testing to show the differences between the selec terrain modes.